MESOSCALE DISCUSSION 0130
NWS STORM PREDICTION CENTER NORMAN OK
0636 PM CDT THU MAR 19 2015
AREAS AFFECTED...N TX
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 192336Z - 200100Z
PROBABILITY OF WATCH ISSUANCE...5 PERCENT
SUMMARY...THREAT FOR ISOLATED LARGE HAIL...AND POTENTIALLY GUSTY
OUTFLOW WINDS...WILL PERSIST FOR ANOTHER 1-2 HOURS /THROUGH ABOUT
01Z/. THE CLAY COUNTY TX SUPERCELL IS LIKELY NEAR PEAK AS IT
INTERACTS WITH THE SURFACE FRONT.
DISCUSSION...ISOLATED STORMS FORMED EARLIER TO THE E OF THE TRIPLE
POINT IN NW TX...AND THIS CONVECTION HAS MOVED EWD INVOF A
QUASI-STATIONARY SURFACE FRONT. THE THERMODYNAMIC ENVIRONMENT IN
THE OPEN WARM SECTOR IS MARGINALLY FAVORABLE FOR SUPERCELLS WITH
EFFECTIVE BULK SHEAR NEAR 40 KT...MIDLEVEL LAPSE RATES AOB 6.5
C/KM...AND MLCAPE AROUND 500 J/KG. LOW-LEVEL SHEAR IS STRONGEST
ALONG AND N OF THE SURFACE FRONT WHERE THE STORMS ARE NOW...BUT
SURFACE-BASED BUOYANCY WEAKENS RATHER QUICKLY WITH EWD/NEWD EXTENT
ACROSS THE FRONT. THUS...THE ONGOING STORMS /PRIMARILY THE CLAY
COUNTY SUPERCELL/ APPEAR TO BE NEAR PEAK INTENSITY AS THE UPDRAFT
INTERACTS WITH THE SURFACE FRONT. THE STORMS MAY REMAIN WITHIN THE
FRONTAL ZONE FOR THE NEXT HOUR OR SO WITH ESEWD PROPAGATION...BUT
GRADUAL BOUNDARY LAYER STABILIZATION AND SLOW SWD MOVEMENT OF THE
FRONT THIS EVENING SUGGEST THAT THE CONVECTION WILL BEGIN TO WEAKEN
FROM 00-01Z. IN THE INTERIM...MARGINALLY SEVERE HAIL AND GUSTY
WINDS WILL BE POSSIBLE.
..THOMPSON.. 03/19/2015
ATTN...WFO...FWD...OUN...SJT...
LAT...LON 33539742 33289717 33089725 32999765 33089816 33099860
33069881 33229904 33529893 33789854 33819805 33699775
33539742